The present invention relates to a fastener that is constructed and arranged for pre-assembly with a first object, typically a panel or the like, that will later be secured to a second object, often a structural member of the interior of an aircraft or an automobile.
A typical fastener used in the aircraft and automobile industries for fastening panels such as a headliner panel into the interior of an aircraft or an automobile is illustrated in FIG. 1 at 10. The prior art fastener 10 is comprised of a large, mushroom-shaped head 12 and has a shank 14 extending from the underside thereof. A shank fastener 16 is formed into the shank 14 and provides the means whereby fastener 10 may secure a first object 20 to a second object 22. The first object, in this instance a headliner panel for an aircraft or automobile, has a bore 24 formed therethrough that is sized to permit the shank 14 of the fastener 10 to pass therethrough. The shank 14 is subsequently inserted into a bore 26 formed through the second object 22, in this case the sheet metal structural member of the interior of an aircraft or automobile. The shank fastener 16 ensures that the fastener 10 cannot be removed from the bores 24 and 26. In this manner, a headliner panel for an aircraft or automobile may be rapidly and easily emplaced.
It is often the practice that various sub-assemblies, such as the headliner panel described above, are manufactured at a location remote from that at which the aircraft or automobile is itself assembled. In this case the sub-assembly is brought to the location where the aircraft or automobile is being assembled and is emplaced at the appropriate time. To facilitate this process wherein parts are manufactured remote from a main assembly location, it is desirable to pre-assemble certain structures such as the headliner panel described above. However, fasteners 10 of the type illustrated in FIG. 1 are not susceptible of pre-assembly with a panel structure as illustrated. Specifically, the shank fastener 16 is not typically formed in a fashion that would retain the fastener 10 in the bore 24 formed in the panel 20. Consequently, the fasteners 10 would most likely work their way out of a bore 24 on their own prior to assembly. In order to permit the pre-assembly of structures such as a headliner panel, small retaining structures have been added to fasteners 10 in order to retain the fasteners in a bore 24 formed through a headliner panel 20 or the like. These retaining structures typically comprise such things as the whiskers 30 illustrated in FIG. 2a or the flexible wings 32 illustrated in FIG. 2b. 
While the retaining structures 30, 32 illustrated in FIGS. 2a and 2b are sufficient to secure a fastener 10xe2x80x2 or 10xe2x80x3 within a bore 24 formed in a sub-assembly 20 such as a headliner panel, the structures are less than ideal in that the fasteners 10xe2x80x2 and 10xe2x80x3 have a tendency to be very loosely held in the bore 24 formed through the sub-assembly 20. This results in difficulty in aligning a fastener 10xe2x80x2, 10xe2x80x3 so that it can be inserted into a bore 26 formed in a second object 22. This inability to align the fasteners 10, 10xe2x80x2, and 10xe2x80x3 can result in increased assembly time and even in broken or lost fasteners.
Accordingly, it is a feature of the present invention to provide a fastener that can be securely and rapidly pre-assembled with a first object such as a headliner panel of an aircraft or an automobile. It is another feature of the present invention to provide a fastener that, once pre-assembled with a first object, remains within a predefined deviation from a predetermined geometric orientation, preferably perpendicular, with the first object. A last feature of the present invention is to provide a method for assembling a first object with a second object that includes the use of a fastener that can be rapidly and securely pre-assembled with the first object in a location remote from the location where the first and second objects are to be assembled, and wherein the fastener maintains a predetermined geometric relationship with the first object to permit the rapid assembly of the first object with the second object.
These and other features and advantages of the invention will appear more fully from the following description, made in conjunction with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views.
The benefits of the present invention are realized in a fastener that comprises at least one pre-assembly leg constructed and arranged to compress a first object between a head of the fastener and the pre-assembly leg. A fastener according to the present invention has a head from which extends a shank having a typical shank fastener for securing the fastener within a bore in a second object. The pre-assembly leg is secured to the shank at a predetermined offset distance from the head and is secured to a lower head at its distal end. The lower head a bore formed therethrough that allows the lower head to be received over the shank and move between a first position located adjacent the tip of the shank and a second position in which the lower head is located adjacent the upper end of the pre-assembly legs. Note that while it is preferred to utilize two pre-assembly legs the present invention may accommodate any useful number. A retaining structure comprised of a combination of flexible tabs and/or catches formed into the shank and extending laterally therefrom is used to retain the lower head in its second position.
It is preferred to construct and arrange the pre-assembly legs such that when the lower head is in its second position, the pre-assembly legs will be biased against a first object through which the fastener has been inserted. However, it is to be understood that the assembly legs may be positioned substantially perpendicular to the shank of the fastener or even biased away from the first object when the lower head is in its second position as required. Note also that, while the pre-assembly arms are preferably folded into their actuated position, the pre-assembly legs may also be bent into a bow or loop shape as well. In any case, the pre-assembly arms act to maintain the fastener in a predetermined geometric relationship with the first object.
In use, the fastener of the present invention is part of a method of assembling a first object to a second object. A first step in this method is to provide a fastener that is constructed and arranged according to the principles of the present invention. The shank of this fastener is then inserted into a bore formed through the first object such that the upper head of the fastener is in contact with the first side of the first object. The lower head of the fastener is then moved from its first position to its second position so as to actuate the pre-assembly legs into a position that retains the fastener of the present invention within the bore formed in the first object. Subsequent to this pre-assembly, the first object, having fasteners of the present invention pre-assembled therewith, is brought to the main assembly location where the first object is aligned with a second object to which it is to be secured. The shank of each of the fasteners of the present invention is then forced into a bore formed into the second object such that the shank fastener will secure each one of the fasteners within that bore in the second object.